West central Michigan apple maturity report – October 9, 2024
Aztec Fuji and EverCrisp are being harvested at some sites this week in the West Central region.
In the West Central region, Idared harvest continues, and some growers are harvesting Aztec Fuji and EverCrisp this week. Pink Lady are close to maturity (Figure 1).
Weather over the past week has been sunny and cool with high temperatures ranging from upper 50s to mid 70s. Lows have ranged from the low 50s to the low 40s with dips down into the upper 30s in Hart according to the MSU Enviroweather Station. Weather conditions have been excellent for fall color development, and sugar levels have improved for late season apple varieties. High temperatures will remain in the 50s and 60s for the rest of this week with a warm day this Friday with the high in the 70s. Conditions will be sunny and dry this week with chances of rain this weekend. Lows will be in the 40s and 30s over the next week with a chance of snow forecasted for next Tuesday.
How to read maturity tables
Each week, an apple maturity report will be provided and will include average values for several apple samples for varieties nearing maturity. Maximum and minimum values a
re included in tables below for the highest and lowest individual fruits evaluated for each to give a full spectrum of maturity. All samples included in the reorts have been untreated with ReTain or Harvista, unless otherwise noted. Samples were collected from two to five locations across Oceana County (Figures 2-3).
For more information about apple maturity testing, review these resources compiled by the Michigan State University Extension tree fruit team.
- Predicted apple harvest dates for 2024 from MSU.
- More information on harvest management tools and timings can be found in this article.
- Guidelines from MSU to check for apple maturity in your own orchard, including specific pressure and starch recommendations by variety.
- New starch charts for evaluating apple maturity in Michigan from Michigan State University
- Predicting apple maturity and starch chart from Cornell University.
- Starch chart for Honeycrisp Apples developed by Washington State University.
Maturity information for the west central region
Aztec Fuji
Fruit were sampled at three locations in Oceana County this week. Fruit are mature, and this variety is being harvested at many locations this week. Red color development has improved since last week, and background color is light green. Firmness is 16.5 lbs pressure, and 17 lbs of pressure is the target pressure for mid-term storage. Starch is 3.3, and sugar is excellent at 13.9°Brix.
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
Sept 23 |
205 (231-188) |
83 (99-60) |
4.1 (5-3) |
17.5 (19.3-16.1) |
2.5 (4-2) |
13.1 (14.0-12.6) |
Sept 30 |
210 (243-177) |
76.2 (95-55) |
2.9 (4-2) |
16.5 (20.2-12.5) |
3.7 (5-2) |
13.0 (13.8-12.1) |
Oct 7 |
195 (229-158) |
89 (99-60) |
3.8 (5-2) |
16.5 (18.4-14.0) |
3.3 (6-2) |
13.9 (14.8-12.8) |
EverCrisp
Fruit were sampled at four locations in Oceana County this week. Fruit are mature at some sites and have been harvested at some locations this week. Red color has improved from last week with an average of 81% although red color varied by location. Background color is light green. Fruit are very firm, and firmness is 20.6 lbs pressure. Starch is 2.8, and sugar is excellent at 15.4°Brix.
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
Sept 30 |
237 (264-213) |
58 (85-40) |
3.16 (4-2) |
21.4 (27.4-17.3) |
2.9 (7-1) |
15.1 (17.4-13.3) |
Oct 7 |
245 (258-233) |
81 (98-45) |
3.9 (5-1) |
20.6 (24.3-17.325) |
2.8 (5-1) |
15.4 (15.6-15.1) |
Pink Lady
Fruit were sampled at three locations in Oceana County this week. Fruit are immature. A pink blush is improving on the fruit and was observed at 64%. Background color is light green. Fruit firmness decreased from last week to 17.6 lbs pressure. Starch is 2.9, and sugar is excellent at 13.0°Brix.
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch (1-8) |
Soluble Solids (°Brix) |
Sept 30 |
191 (195-186) |
43 (55-35) |
3.1 (4-3) |
20.6 (25.1-17.3) |
1.9 (4-1) |
13.0 (13.7-12.3) |
Oct 7 |
177 (176-179) |
64 (95-45) |
3.6 (4-2) |
17.6 (20.6-14.6) |
2.9 (5-1) |
13.0 (13.7-12.2) |
Apple maturity sampling parameters
- Color % = the visual percentage of red color from 0 to 100; range is of all fruits tested. Indicates surface area covered in red and intensity of red color.
- Background color: 5 = Green, 1 = Yellow; range is of all fruits tested.
- Firmness in pounds pressure = measured with a Güss Fruit Texture Analyzer; range is of all fruits tested.
- Starch for Honeycrisp: will typically be rated using the standard Michigan State University starch scale (1-8). However, a separate starch chart for Honeycrisp apples developed by Washington State University (scale 1-6) also exists.
- Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
Looking for more? View Michigan State University Extension’s Apple page for regional reports throughout the state and additional resources.
Suggested firmness and starch index levels for long-term and shorter-term controlled atmosphere (CA) storage by variety. |
|||||
---|---|---|---|---|---|
Variety |
Firmness (pounds)* |
Starch Index* |
|||
Short CA |
Mid-CA |
Long CA |
Mature |
Over mature |
|
McIntosh |
14 |
15 |
16 |
5 |
7 |
Gala |
16 |
17 |
18 |
3 |
6 |
Honeycrisp |
15 |
16 |
17 |
3.5 |
6 |
Empire |
14 |
15 |
16 |
3.5 |
6 |
Early Fuji |
16 |
17 |
18 |
3 |
7 |
Jonagold |
15 |
16 |
17 |
3.5 |
5.5 |
Jonathan |
14 |
15 |
16 |
3.5 |
5.5 |
Golden Delicious |
15 |
16 |
17 |
3 |
6.5 |
Red Delicious |
16 |
17 |
18 |
2.5 |
6 |
Idared |
14 |
15 |
16 |
3.5 |
6 |
Fuji |
16 |
17 |
18 |
3 |
7 |
Rome |
15 |
16 |
18 |
3 |
5.5 |
Brix Guide |
Low |
Fair |
Good |
Excellent |
---|---|---|---|---|
All varieties |
Less than 11 |
11 |
12 |
13 |
Honeycrisp |
Less than 12 |
12 |
12 |
Greater than 14 |